It is known to exchange data, such as message data, between mobile devices (also known as “mobile terminals”) in a communication system, such as a mobile (otherwise known as a “cellular”) telephone system. In GSM networks, for example, it is possible to exchange simple text messages between mobile devices. Such text messages utilize GSM's Short Message Service (SMS) and are typically limited to 160 characters. Modern mobile networks often also allow richer messages containing pictures or audio to be transmitted between mobile devices. However, the extent to which these additional types of messages can be used depends on the mobile devices involved.
There are many types of mobile devices which may have various capabilities. For example, some mobile devices are only able to place and receive calls. However, other mobile devices also have data capabilities, such as the ability to display text, display graphics, play sound and/or access the Internet.
Additionally, different mobile devices may be able to receive different types of formatted data. For example, some mobile devices may support data formats such as .gif, .jpg, .mpeg, .midi, .wav, while others may support only some or none of these formats. There may also be differences regarding the size of message that a particular mobile device can support. Further, there can be differences in the message attributes supported by mobile devices. For example, some mobile devices may support delivery notification, while others may not. With all of these differences, a user of a mobile device sending a message to a receiving mobile device may not know whether and how the message will appear on the receiving mobile device. The format of the message when it is received may be quite different from the format of the message when it was sent.
To tackle these incompatibilities, networks may offer the possibility of transcoding individual components of data messages or their attachments. Transcoding typically involving re-formatting components of a data message, which may make it possible for a receiving device to interpret the sequence of transcoded components and hence the content of a message, even if the message originally contained components that were not suitable for the receiving device. However, the format of the message may be changed using the transcoding. In addition, transcoding requires relatively complicated data processing which involves additional hardware and software and which increases the handling time and cost. Also, the message may be corrupted by the transcoding process.
It is an object of the present invention to overcome these and other problems of the Prior Art and to provide a method of transmitting data in a communication system that allows data messages to be exchanged between devices having distinct capabilities while avoiding transcoding of the data messages.
It is another object of the present invention to provide a device and a mobile communication system in which said method is utilized.